Bending machine



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BENDING MACHINE Filed Sept. 5, 1964 4 Sheets-Sheet 5 'INVENTOR. 45 HANS SCHMIDT UHHIHI f l Q .9 51

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BENDING MACHINE Filed Sept. 5, 1964 4 Sheets-Sheet 4 A INVENTOQ m HANS SCHMIDT BY United States Patent 3,333,450 BENDING MACHINE Hans Schmidt, Aurora, Ill., assignor to Pines Engineering Co., Inc., Aurora, Ill., a corporation of Illinois Filed Sept. 3, 1964, Ser. No. 394,220 9 Claims. (Cl. 72-456) This invention relates to improvements in machines for bending tubes, pipes, rods and like stock and is particularly concerned with apparatus useful in producing a series of reverse bends of 180 in tubular stock.

More specifically, the machine includes a two-piece bending die wherein the die components are movable toward and away from each other during loading and unloading operations and which are securely locked together during the bending operation so as to prevent their spreading apart. One die component is mounted for rotation firmly on a bed whereas the other die component is carried by a vertically reciprocable carriage and spindle assembly so as to be movable toward and away from the firmly held die component. The structure includes novel means operable when the die components are brought together for locking the movable die component against movement away from the firmly mounted die component. During a bending operation both die components are rotated in unison to perform the required bend in the stock and when the die components are separated, means individual to each die component is brought into operation to return the die components to their initial or starting positions for repeat operation.

It is, therefore, an object of this invention to provide a bending machine of novel construction.

Another object is to provide, in a bending machine, a pair of matching bending die components of novel construction that are movable toward and away from one another.

Another object is to provide novel means to lock a pair of matching bending die components together and in a manner to resist their movement away from one another during a bending operation.

Another object is to provide a hydraulically actuated locking jaw mechanism of novel construction.

Another object is to provide a machine of the character described which is not too expensive to manufacture, is positive in its operation, entirely automatic and very efiicient in use.

The structure by means of which the above noted and other advantages and objects of the invention are attained will be described in the following specification, taken in conjunction with the accompanying drawings, showing a preferred illustrative embodiment of the invention, in which:

FIG. 1 is a side elevational view of the bending machine showing the die components matched and in contact one with the other;

FIG. 2 is a schematic view of the drive for the lower die component, viewed along line 2--2 of FIG. 1;

FIG. 3 is an enlarged side elevational view of the carriage and spindle assembly for the upper die component;

FIG. 4 is a top plan view of the structure shown in FIG. 3;

FIG. 5 is a vertical sectional View of the lower bending die component assembly;

FIG. 5a is an enlarged elevational view of the spindle assembly, showing parts broken away and in section and illustrating the jaws in closed position;

FIG. 6 is an enlarged sectional detail view of one of the jaws, showing it in open position;

FIGS. 7, 8 and 9 are schematic views illustrating the steps of the bending operation;

3,333,450 Patented Aug. 1, 1967 FIG. 10 is an end and elevational view of the lower die component, viewed substantially along line 10-10 of FIG. 7; and

FIG. 11 is a view of assembled lengths of tubular stock bent by the machine.

Referring to the disclosure in the drawings of an eX- emplary machine embodying the invention, the machine includes a built up base structure 11 of substantial length upon which is mounted a top beam 12 that overhangs the greater portion of the base structure to provide an open yoke 13. Specifically, the beam 12 is mounted firmly on the upper end of an upright extension 14 at the rear end of the base structure.

The base structure 11 is a rigidly mounted elongated hollow shell and is open on its upper face. Mounted within the base and substantially coextensive with its length is an elongated housing 15 suitably supported in any acceptable manner so as to be vertically adjustable for the purpose of aligning the bending dies with stock feed mechanism not shown. When adjusted, the housing 15 is secured firmly in place within the base structure 11.

The elongated housing 15 mounts, at what might be termed its forward end, a vertically journalled stud shaft 16 carrying a pair of sprockets 17 over which are trained a pair of chains 18. One common end of these chains is connected, as at 19 (FIG. 2) to the piston rod 21 of a hydraulic piston-cylinder assembly 22. The other ends of said chains are each connected to a rod 23 having chains 24 connected to its other end and which are trained over and secured to idler sprockets 25. It should be evident that when the piston-cylinder assembly 22 is actuated there is imparted positional rotation of stud shaft 16. The stud shaft 16 mounts firmly at its upper end an axial post 26 (FIG. 5) of considerable length. This post has reduced diameter 27 adjacent to its upper end defining a head 28 A bending die component 29 is fitted firmly, as by press fitting, over the post 26 so as to be rotated with stud shaft 16. The lower bending die component, best shown in FIGS. 7 and 10, is comprised of a single block of metal stock suitably rounded at one end and formed on said end with a quarter circle concave surface 31 which surface extends along the straight sides thereof to define onefourth of the bending die cavity. A block 32 is secured to the upper face of the die component and has a semi-circular channel 33 on its upper surface in substantial register with one terminal end of concave surface 31.

The top beam 12 overhangs the forward end of housing 15 and mounts, in vertical axial alignment with stud shaft 16, a spindle assembly generally indicated at 34. This spindle assembly 34 is carried in a vertically reciprocable carriage 35 mounted on the front end of beam 12. Vertical reciprocation of said carriage and the spindle assembly carried thereby, may be effected upon operation of a reciprocable piston-cylinder assembly 36.. It is sufiicient to note for purposes of this disclosure, that upon admittance of hydraulic pressure into either end of said pistoncylinder assembly 36, the carriage 35 is raised or lowered away from or toward the lower die component 29.

The spindle assembly 34, best shown in FIG. 5, comprises a cylinder 37, having an axial sleeve 38 rigidly secured to and depending therefrom. The cylinder 37 contains a piston 39 that is secured firmly to a plunger rod 41 which mounts, on its lower end, a chuck assembly 42. As shown, the chuck assembly includes a collar 43 that is threaded and locked on the lower end of plunger rod 41. The bottom end of said collar is bifurcated to receive in each bifurcation, a jaw 44. These jaws, of which there are three, are alike and each has a radially directed flange 45 on its inside bottom surface. Each jaw is pivoted on a pin 46 and its outside surface above said pin is formed with a tongue 47 and a cut-back 48.

This tongue and cut-back are arranged to cooperate with an internal circumferential flange 49 on the bottom edge of sleeve 38 in a manner and for a purpose to be described presently.

Referring to FIG. 3, the spindle assembly 34 is sus pended from and secured to the upper end of a rotatable shell 51, mounted within a cylindrical body 52 formed integral with the vertically reciprocable carriage 35. Suitable anti-friction bearings 53 minimize friction between shell 51 and body 52. Secured firmly to the bottom end of shell 51 is an upper die component 54. This die component has all the characteristics of the lower die component 29 except that it is in reverse position to match with and complement the lower die component 29 and define a stock receiving peripheral groove 55. The upper bending die component 54 is apertured axially so as to receive post 26 upwardly therethrough freely when the die components are in mating engagement as shown in FIG. 3.

When the bending die components are brought into mating engagement upon lowering of the reciprocable carriage 35, the jaws 44 are spread apart initially, as shown in FIG. 6, by admitting hydraulic pressure through a line 56 above piston 39. This enables the jaws to move downwardly past the post head 28. Just prior to the carriage and upper pressure die 54 reaching their lowermost positions, the hydraulic pressure is relieved in cylinder 37 and, as the carriage approaches the limit of its downward stroke, its internal flange 49 engages with the jaws 44 (FIG. 5) to rock them inwardly so as to embrace the post recess 27 firmly. This locks the two die components 29, 54 together so as to resist their tendency during a bending operation to spread apart vertically. Such tendency to spread is generated as the die components are rotated.

Prior to bending rotation of the bending die components, a clamp shoe 57 is carried into engagement with the stock S adjacent to said bending die components. This is actuated by a hydraulic piston-cylinder assembly 58 (FIG. 1).

Rotation of the bending die components, in unison in one direction for bending, is accomplished by applying hydraulic pressure to the forward end of the hydraulic piston-cylinder assembly 22. This rotates the die components from the starting position illustrated in FIG. 7, into the full bending position illustrated in FIG. 8. The stock is thus bent to form an 180 bend.

Following the bending, the clamp shoe 57 is relieved and the bending die components are separated. The stock then is pushed, manually or automatically, in a forward direction to carry the bent portion clear of the bending die components.

The pressure in the piston assembly 22 is then relieved returning the lower bending die to its loading position and a hydraulic motor 58 mounted on carriage 35 (FIGS. 3-4) is operated to return the upper die component to its loading position. This motor carries on its shaft a sprocket 59 over which is trained a chain 61. The chain is carried around a large sprocket 62 mounted firmly on the upper end of sleeve 51 so that when the motor operates, the sleeve and the upper bending die component 54 return to their initial start or loading position.

The stock is successively rotated 180 about its axis (FIG. 9) and repositioned in the bending die for repeat bending operation. As successive bends are made in the stock, its bulk is readily received in the open yoke 13.

In actual production, it is proposed to arrange two bending machines side by side with different size bending dies in each. Thus, after a bend is formed in the stock by a first machine, said stock is axially rotated as aforesaid and pushed into a bending position in the bending dies of a second machine and a bending operation performed thereon. After this bend is performed, the stock is again axially rotated and returned to position in the first machine for repeat bending. These sequential operations can be repeated as often as required to produce a serpentine coil such as is illustrated in FIG. 11.

As shown in FIG. 11, the bends 63 at one side thereof are of uniform diameter whereas the bends 64 at the other side thereof are of a uniform smaller diameter. This permits the assembly, in use, of two such coils in a side by side relationship as illustrated. Of course only one machine may be used during which use all bends in the stock are uniform.

Although I have described a preferred embodiment of my invention, in considerable detail, it will be understood that the description thereof is intended to be illustrative, rather than restrictive, as many details of the structure disclosed may be modified or changed without departing from the spirit or scope of the invention. Accordingly, I do not desire to be restricted to the exact construction described.

I claim:

1. In a machine for bending tubular stock and like material, an elongated base, a beam supported firmly above and spaced from said base, a rotatable die component mounted in said base, a spindle assembly carried by said beam in axial alignment with said die component, a complemental die component carried by the spindle assembly and normally spaced above the base mounted die component, means to move the spindle assembly and its die component downwardly to carry said die component into face to face abutment with the base mounted die component, matching means on said die components to engage a piece of stock firmly, means to rotate said die components in unison on a vertical axis to bend stock, and chuck means to lock said die components against separation during the bending operation.

2. In a machine for bending tubular stock and like material, an elongated base, a beam supported firmly above and spaced from said base, a rotatable die component mounted in said base, a spindle assembly carried by said beam in axial alignment with said die component, a complemental die component carried by the spindle assembly and normally spaced above the base mounted die component, means to move the spindle assembly and its die component downwardly to carry said die components into face to face abutment, means to rotate said die components in unison on a vertical axis during a bending operation, and chuck means to lock said die components against separation during the bending operation.

3. In the machine recited in claim 2, in which separate means is provided to return each bending die component to starting position after the bending operation.

4. In a machine for bending tubular stock and like material, the combination of a base, a rotatable trunnion mounted on a vertical axis in said base, a bending die component mounted firmly on said trunnion, a spindle assembly mounted in axial alignment with and above said bending die component, a complemental bending die component carried by said spindle, means to raise and lower the spindle assembly for moving the second die component toward and away from the first named die component, means carried by the spindle assembly engageable with means integral with the first bending die component to lock the complemental bending die components in face to face engagement, common drive means to rotate said die components in unison in one direction for bending stock, and separate drive means to rotate the die components in another direction.

5. In a machine for bending tubular stock and like material, the combination of a base, a rotatable trunnion mounted on a vertical axis in said base, a bending die component mounted firmly on said trunnion, a post extension on said trunnion extending through said bending die component and beyond the upper face of said component, a spindle assembly mounted in axial alignment With and above said bending die component, a complemental bending die component carried by said spindle, means to raise and lower the spindle assembly for moving the second die component toward and away from the first named die component, means carried by the spindle assembly engageable with the post to lock the complemental bending die components in face to face engagement, common drive means to rotate said die components in unison in one direction for bending stock, and separate drive means to rotate the die components individually in the other direction.

6. In a machine for bending tubular stock and like material, the combination of a base, a lower bending die component mounted on said base for rotation on a vertical axis, a vertically reciprocable spindle assembly mounted above said bending die component and in axial alignment therewith, an upper bending die component carried by said spindle assembly, means to raise and lower the spindle assembly and its die component to carry the upper die component into and out of face to face engagement with the lower die component, a post extending upwardly from the lower die component, means carried by the spindle assembly to engage with said post to lock the bending die components together when in face to face engagement, and means operable to rotate both bending die components in unison.

7. In a machine for bending tubular stock and like material, the combination of a base, a lower bending die component mounted on said base for rotation on a vertical axis, a vertically reciprocable spindle assembly mounted above said bending die component and in axial alignment therewith, an upper bending die component carried by said spindle assembly, means to raise and lower the spindle assembly and its die component to carry the upper die component toward and away from the lower die component, a post on the base extending upwardly through the lower die component, and means carried by the spindle assembly to engage with said post to lock the bending die components together when the spindle assembly is in a lowered position.

8. In the machine recited in claim 7, in which the means carried by the spindle assembly comprises a post engaging chuck.

9. In a machine for bending tubular stock and like material, a pair of bending die components arranged to have face to face engagement, an annular channel common to the perimeter surfaces of both components to receive a length of stock therein, means on. said components to embrace the stock firmly, means to rotate the bending die components'in unison so as to bend the stock, and clutch means to prevent relative axial movement of said components during a bending operation.

References Cited UNITED STATES PATENTS 2,814,327 11/1957 Charlton 72-159 X CHARLES W. LANHAM, Primary Examiner. R. D. GREFE, Assistant Examiner. 

1. IN A MACHINE FOR BENDING TUBULAR STOCK AND LIKE MATERIAL, AN ELONGATED BASE, A BEAM SUPPORTED FIRMLY ABOVE AND SPACED FROM SAID BASE, A ROTATABLE DIE COMPONENT MOUNTED IN SAID BASE, A SPINDLE ASSEMBLY CARRIED BY SAID BEAM IN AXIAL ALIGNMENT WITH SAID DIE COMPONENT, A COMPLEMENTAL DIE COMPONENT CARRIED BY THE SPINDLE ASSEMBLY AND NORMALLY SPACED ABOVE THE BASE MOUNTED DIE COMPONENT, MEANS TO MOVE THE SPINDLE ASSEMBLY AND ITS DIE COMPONENT DOWNWARDLY TO CARRY SAID DIE COMPONENT INTO FACE TO FACE ABUTMENT WITH THE BASE MOUNTED DIE COMPONENT, MATCHING MEANS ON SAID DIE COMPONENTS TO ENGAGE A PIECE OF STOCK FIRMLY, MEANS TO ROTATE SAID DIE COMPONENTS IN UNISON ON A VERTICAL AXIS TO BEND STOCK, AND CHUCK MEANS TO LOCK SAID DIE COMPONENTS AGAINST SEPARATION DURING THE BENDING OPERATION. 